Structural element for high temperature service use



Patented Jan. 11, 1949 STRUCTURAL ELEMENT FOR HIGH TEMPERATURE SERVICEUSE Arthur '1. Cape, Columbus, Ohio, assignor to Coast Metals, Inc.,Canton, Ohio, a corporation of Delaware No Drawing. Application June 30,1944, Serial No. 543,047

5 Claims. (75-171) This invention relates in general to alloys, but hasreference more particularly to alloys which are especially adapted forhard facing purposes as well as for use in the form of castings.

In my United States Letters Patent No. 2,396,552, granted March 12,1946, I have described an alloy which is especially useful for the hardfacing of valves and valve seats, due principally to its resistance tothe attack of lead oxide and other lead compounds found in or resultingfrom the combustion of so-called leaded gasoline. The alloy in that caseconsisted principally of nickel, chromium, tungsten and cobalt with thenickel present in amounts of 35% to 55%, the chromium in amounts of 25%to 40%, the tungsten in amounts of 10% to 20% and the cobalt in amountsup to 12%.

I have discovered that the cost of such an alloy can be considerablyreduced, while maintaining, and in some instances, improving theresistance of the alloy to the attack of lead oxide, by increasing thenickel content of the alloy to a range of from 55% to 75%, lowering thechromium range to 10% to 30%, utilizing a tungsten range of 10% to13.5%, and eliminating cobalt as a constituent of the alloy.

An alloy, in accordance with the invention, may contain the followingconstituents or elements in the stated ranges:

Percent Nickel 55 to 75 Chromium 10 to 30 Tungsten 10 to 13.5 Carbon Upto 3. 5 Iron Balance but not more than 10 The carbon may be replaced inwhole, or in part by boron, for the purpose of controlling primarily thealloys melting point which is reduced by increasingly larger amounts ofboron, the practical limit being of the order of 3%. In most cases,however, acarbon content of from about 1.75% to 2.75% is preferred.

A preferred alloy within the range stated above has the followingapproximate analysis:

Percent Nickel 65 Chromium 20 Tungsten 11. 5 Carbon 2. Iron 1.

Alloys made in accordance with the invention are particularly resistantto the attack of lead oxide and other lead compounds found in orresulting from the combustion of the so-called leaded gasolines, and forthis reason are especially adapted for the hard facing of valves andvalve seats in internal combustion engines which utilize such fuels.

2 While the utility of the alloy for hard facing purposes has beenemphasized, it is to be understood that the alloy may also be utilizedfor making castings.

Having thus described my invention, I claim:

1. A structural element having at least a part which in use is subjectedto abrasion and wear at elevated temperatures, and which is capable ofresisting the corrosive action of lead oxide at those temperatures, saidpart comprising an alloy containing from about 55% to about 75% nickel,from about 10% to about 30% chromium, from about 10% to about 13.5%tungsten, and from about 1.75% to about 3.5% carbon, the balance of thealloy being substantially all iron, but the iron being not in excess of10%.

2. A structual element, as defined in claim 1, in which the carbon iswithin the range of from about 1.75% to about 2.75%.

3. A structural element, as defined in claim 1, said element beingavalve.

4. A structural element having at least a part which in use is subjectedto abrasion and wear at elevated temperatures, and which is capable ofresisting the corrosive action of lead oxide at those temperatures, saidpart comprising an alloy containing about nickel, about 20% chromium,

about 11.5% tungsten and about 2% carbon, the

balance of the allow being iron.

5. A structural element, as defined in claim 4, said element being avalve.

ARTHUR T. CAPE.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS OTHER REFERENCES Woldman et al., EngineeringAlloys, 1936, page 174; Alloy No. 1909; published by American Societyfor Metals, Cleveland, Ohio.

